Gms with fungus other than the control fungus staining

We are having a problem with a contaminate fungus that is being picked up
with the gms stain on cytospins. The patient slide is contaimated with a
fungus. We use sterile water for our water rinses, and the stock and
working solutions are made up with sterile water also. We don't make the
cytospins. Th cytology person makes them. This happened with a case last
week and also this week. The other cases that the gms was done on did not
have anything else staining that was not supose to. These were case that we
cut. The water baths have sterile water also. If anyone has a probable
solution for this problem, that we have not considered please reply.
Allison Scott